<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>


        var m = new Map([[1, 'x'], [2, 'y'], [3, 'z']]);
        alert(m);
        m.forEach(function (value, key, map) {
            alert(value);
        });


    </script>
</head>
<body>

</body>
</html>